As social applications are extensively used, a proximity discovery function becomes increasingly important. For example, users wish to know presence or absence of their friends in the vicinity in a timely manner. The proximity discovery function makes people's life and work more convenient. For example, after a user arrives at an office, the user can use the proximity discovery function to quickly know which colleagues will soon arrive at the office.
A method for proximity discovery provided by the prior art is implemented based on an absolute position of a user equipment (User Equipment, hereinafter briefly referred to as UE), where judgment for proximity discovery is mainly based on a cell identity. Therefore, if the radius of a cell is large, an error of a distance between UEs will be enlarged; and it is possible that two UEs close to each other but belonging to two neighboring cells are determined to fall beyond a proximity range. Therefore, the method provided by the prior art has a large error and low accuracy in proximity discovery.
In addition, the method provided by the prior art is implemented by an application server in a network. The network of an operator provides only a pipeline function for information transmission between a user equipment and the application server. Although the network of the operator undertakes enormous network resource overheads for a proximity discovery service, the operator cannot benefit from this service.